Now, 16 months later, of four hospitalized workers, Ricky Mejia, who spent 11 days in the hospital – two breathing with the help of a mechanical ventilator – still is suffering from lung ailments and other health problems. He uses an inhaler, and misses some work because of his illness.
Morales Zavala, 48, the shearing machine operator who pierced the unlabeled cylinder tank and ran to warn the staff, is still on the job, suffering from poor health, including stomach problems. Fellow workers say he has lost 40 to 50 pounds, and has a hard time eating.
As for two other hospitalized employees, Danni Cuevas, 23, is back at work after recuperating for weeks, and Gladis Alaniz, 29, a clerk, has left the company.
The first responders were initially told that a 300-gallon tank had ruptured, perhaps containing ammonia, said firefighter-paramedic Karl Kassner with the Visalia Fire Department Hazardous Materials Response Team.
But when the firefighters in self-contained suits got close and sent camera images to the haz-mat trailer where Kassner and others waited, “we saw the one-ton cylinder and knew right away it was more than likely liquid chlorine that had been under pressure. We could hear the team's chlorine alarm going off,” Kassner said. When he called on the radio and learned the concentration was 328 ppm, they all knew that it remained at a level known to firefighters as “immediately dangerous to life and health,” even three hours after the original release.
Sometimes when Martinez looks at any cylinder, she feels a sense of panic. To the workers, the accident seems like yesterday. They can't shake the feeling of being unable to breathe.
Martinez recalls how the chlorine gas on their clothes made the ambulance drivers cough, and how people driving on the freeway a half-mile away could smell it. She remembers not breathing normally for days, and wanting to take showers every 20 minutes. "Sweat smelling like chlorine poured out of me. My husband said my coughs smelled like chlorine,” she said.
Working about 120 yards from the tank, John Espinola, shop supervisor, felt like his head had been covered in Saran wrap. "You felt like your breath was being taken away. You're engulfed in a yellowish cloud. I was just gasping for air. I couldn't get enough oxygen," he said.
Doctors say people who survive heavy chlorine exposure may suffer acute respiratory distress syndrome. Some people develop chemical pneumonitis, an inflammation of the lungs, from breathing in chemical fumes. They can recover or end up with permanent scarring of the lungs, which reduces their breathing capacity.
Even a one-time high-level exposure can lead to irritant-induced asthma. People develop bronchitis, or inflammation of the airways. In some, but not in all people, the bronchitis induces asthma, said Dr. John Balmes, professor at the University of California at San Francisco and division chief of occupational and environmental medicine at San Francisco General Hospital. Balmes’ laboratory has been studying the respiratory health effects of air pollutants for 25 years, and he reviewed parts of the U.S. Health and Human Services' toxicological profile for chlorine released last year.
What happens when a person breathes chlorine is that the corrosive substance splits hydrogen from water in moist human tissue, releasing oxygen and hydrogen chloride, which do the damage. Scientists say there are palliative remedies but no antidote.
Researchers believe that an injury from chlorine gas to the airway lining – or the epithelium – can somehow lead to persistent airway hyper-responsiveness, Balmes said. Smoking and allergies seem to increase the risk of permanent asthma after chemical exposures.
“Most people get better once they've recovered from the chemical bronchitis. Some don't," Balmes said.